Practical Analysis of Reflectometers and Power Equation Concepts

The theory of power equations [1], [2] introduced a concept whereby the basic parameter is the net power in the waveguide of interest. Power equations are based on the "terminal invariant" parameters: available power, maximum efficiency, and "mismatch factors." The purpose of this paper is to examine the various systems which can be used to satisfy the power equation concept in the transfer of the known effective efficiency of a standard mount to an unknown mount. The equations presented in this paper show that the measurement techniques illustrated in [1], [2] can be simplified. Furthermore, the measurement procedures shown here have been practically used in calibration laboratories for many years and proved to be very effective. This study should make it possible for one to know precisely what is being measured and what system parameters can contribute to measurement inaccuracies. Even though Engen and Beatty [3] have given thorough explanations of precision reflectometers used in measurement systems, there are still some misunderstandings concerning the basic details of tuning procedures.